"As we've all done, we've seen Steve Irwin and the Crocodile Hunter, we thought that we were well-versed in maybe coming up behind it and grabbing it as it wasn't really moving too quickly, so that's what we did.

The Hughes' notified the owners and kept the reptile in their bath until police arrived.

The baby croc is one of two missing from a mobile Sydney wildlife show. (9NEWS) ()The reptile measures 80cm long. (9NEWS) ()

Keepers from Get Wild Animal Experiences - a mobile Sydney wildlife show - had been scouring Georges River since the reptiles' disappearance more than six weeks ago after a report of a crocodile sighting in the water.

Grave concerns were held for the crocs, named Snap and Crackle, as temperatures across the state plummeted.

"We think we managed to get hold of Snap because he did have a few goes when we were bringing him up to put him in the bath, so there is one still out there," Mr Hughes said.

The wildlife business issued an update last night following the crocodile's return.

"He is very cold, thin and lethargic but we are hoping with some TLC he will be back to normal in no time," a statement on the Get Wild Facebook page read.

"We are beyond happy and would like to thank Aaron who contacted us and Kogarah Police for assisting in this matter."

Police have confirmed the crocodile is one of the two stolen from the mobile zoo, but said it was not yet known whether it was Snap or Crackle that had been found.